<!DOCTYPE html>
<html lang="zh-cn">
<head>
  <meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=2">
<meta name="theme-color" content="#222">
<meta name="generator" content="Hexo 5.4.0">
  <link rel="icon" type="image/png" sizes="16x16" href="https://gitee.com/reku1997/reku1997/raw/master/reku.ico">

<link rel="stylesheet" href="/css/main.css">


<link rel="stylesheet" href="/lib/font-awesome/css/font-awesome.min.css">

<script id="hexo-configurations">
    var NexT = window.NexT || {};
    var CONFIG = {"hostname":"reku1997.gitee.io","root":"/","scheme":"Gemini","version":"7.8.0","exturl":false,"sidebar":{"position":"left","display":"post","padding":18,"offset":12,"onmobile":false},"copycode":{"enable":true,"show_result":true,"style":"flat"},"back2top":{"enable":true,"sidebar":false,"scrollpercent":false},"bookmark":{"enable":false,"color":"#222","save":"auto"},"fancybox":false,"mediumzoom":false,"lazyload":false,"pangu":false,"comments":{"style":"tabs","active":null,"storage":true,"lazyload":false,"nav":null},"algolia":{"appID":"AW5K8S9IEE","apiKey":"d7e666d597854738d2fb31ecaa989aa5","indexName":"dev_reku1997","hits":{"per_page":10},"labels":{"input_placeholder":"Search for Posts","hits_empty":"We didn't find any results for the search: ${query}","hits_stats":"${hits} results found in ${time} ms"}},"localsearch":{"enable":false,"trigger":"auto","top_n_per_article":1,"unescape":false,"preload":false},"motion":{"enable":true,"async":false,"transition":{"post_block":"fadeIn","post_header":"slideDownIn","post_body":"slideDownIn","coll_header":"slideLeftIn","sidebar":"slideUpIn"}}};
  </script>

  <meta name="description" content="A. Vladik and Courtesy 二分查找一下次数就行">
<meta property="og:type" content="article">
<meta property="og:title" content="Codeforces Round #416 (Div. 2)">
<meta property="og:url" content="https://reku1997.gitee.io/2017/05/31/codeforces-round-416-div-2/index.html">
<meta property="og:site_name" content="Reku">
<meta property="og:description" content="A. Vladik and Courtesy 二分查找一下次数就行">
<meta property="og:locale" content="zh_CN">
<meta property="article:published_time" content="2017-05-31T10:42:53.000Z">
<meta property="article:modified_time" content="2021-12-16T12:10:02.000Z">
<meta property="article:author" content="Reku">
<meta property="article:tag" content="codeforces">
<meta property="article:tag" content="树DP">
<meta property="article:tag" content="并查集">
<meta property="article:tag" content="二分查找">
<meta property="article:tag" content="交互题">
<meta name="twitter:card" content="summary">

<link rel="canonical" href="https://reku1997.gitee.io/2017/05/31/codeforces-round-416-div-2/">


<script id="page-configurations">
  // https://hexo.io/docs/variables.html
  CONFIG.page = {
    sidebar: "",
    isHome : false,
    isPost : true,
    lang   : 'zh-cn'
  };
</script>

  <title>Codeforces Round #416 (Div. 2) | Reku</title>
  






  <noscript>
  <style>
  .use-motion .brand,
  .use-motion .menu-item,
  .sidebar-inner,
  .use-motion .post-block,
  .use-motion .pagination,
  .use-motion .comments,
  .use-motion .post-header,
  .use-motion .post-body,
  .use-motion .collection-header { opacity: initial; }

  .use-motion .site-title,
  .use-motion .site-subtitle {
    opacity: initial;
    top: initial;
  }

  .use-motion .logo-line-before i { left: initial; }
  .use-motion .logo-line-after i { right: initial; }
  </style>
</noscript>

<link rel="alternate" href="/atom.xml" title="Reku" type="application/atom+xml">
</head>

<body itemscope itemtype="http://schema.org/WebPage">
  <div class="container use-motion">
    <div class="headband"></div>

    <header class="header" itemscope itemtype="http://schema.org/WPHeader">
      <div class="header-inner"><div class="site-brand-container">
  <div class="site-nav-toggle">
    <div class="toggle" aria-label="Toggle navigation bar">
      <span class="toggle-line toggle-line-first"></span>
      <span class="toggle-line toggle-line-middle"></span>
      <span class="toggle-line toggle-line-last"></span>
    </div>
  </div>

  <div class="site-meta">

    <a href="/" class="brand" rel="start">
      <span class="logo-line-before"><i></i></span>
      <h1 class="site-title">Reku</h1>
      <span class="logo-line-after"><i></i></span>
    </a>
  </div>

  <div class="site-nav-right">
    <div class="toggle popup-trigger">
        <i class="fa fa-search fa-fw fa-lg"></i>
    </div>
  </div>
</div>




<nav class="site-nav">
  <ul id="menu" class="menu">
        <li class="menu-item menu-item-home">

    <a href="/" rel="section"><i class="fa fa-fw fa-home"></i>Home</a>

  </li>
        <li class="menu-item menu-item-about">

    <a href="/about/" rel="section"><i class="fa fa-fw fa-user"></i>About</a>

  </li>
        <li class="menu-item menu-item-tags">

    <a href="/tags/" rel="section"><i class="fa fa-fw fa-tags"></i>Tags</a>

  </li>
        <li class="menu-item menu-item-archives">

    <a href="/archives/" rel="section"><i class="fa fa-fw fa-archive"></i>Archives</a>

  </li>
        <li class="menu-item menu-item-sitemap">

    <a href="/sitemap.xml" rel="section"><i class="fa fa-fw fa-sitemap"></i>Sitemap</a>

  </li>
      <li class="menu-item menu-item-search">
        <a role="button" class="popup-trigger"><i class="fa fa-search fa-fw"></i>Search
        </a>
      </li>
  </ul>
</nav>



  <div class="search-pop-overlay">
    <div class="popup search-popup">
        <div class="search-header">
  <span class="search-icon">
    <i class="fa fa-search"></i>
  </span>
  <div class="search-input-container"></div>
  <span class="popup-btn-close">
    <i class="fa fa-times-circle"></i>
  </span>
</div>
<div class="algolia-results">
  <div id="algolia-stats"></div>
  <div id="algolia-hits"></div>
  <div id="algolia-pagination" class="algolia-pagination"></div>
</div>

      
    </div>
  </div>

</div>
    </header>

    
  <div class="back-to-top">
    <i class="fa fa-arrow-up"></i>
    <span>0%</span>
  </div>


    <main class="main">
      <div class="main-inner">
        <div class="content-wrap">
          

          <div class="content post posts-expand">
            

    
  
  
  <article itemscope itemtype="http://schema.org/Article" class="post-block" lang="zh-cn">
    <link itemprop="mainEntityOfPage" href="https://reku1997.gitee.io/2017/05/31/codeforces-round-416-div-2/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/avatar.gif">
      <meta itemprop="name" content="Reku">
      <meta itemprop="description" content="">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Reku">
    </span>
      <header class="post-header">
        <h1 class="post-title" itemprop="name headline">
          Codeforces Round #416 (Div. 2)
        </h1>

        <div class="post-meta">
            <span class="post-meta-item">
              <span class="post-meta-item-icon">
                <i class="fa fa-calendar-o"></i>
              </span>
              <span class="post-meta-item-text">Posted on</span>

              <time title="Created: 2017-05-31 18:42:53" itemprop="dateCreated datePublished" datetime="2017-05-31T18:42:53+08:00">2017-05-31</time>
            </span>
              <span class="post-meta-item">
                <span class="post-meta-item-icon">
                  <i class="fa fa-calendar-check-o"></i>
                </span>
                <span class="post-meta-item-text">Edited on</span>
                <time title="Modified: 2021-12-16 20:10:02" itemprop="dateModified" datetime="2021-12-16T20:10:02+08:00">2021-12-16</time>
              </span>
            <span class="post-meta-item">
              <span class="post-meta-item-icon">
                <i class="fa fa-folder-o"></i>
              </span>
              <span class="post-meta-item-text">In</span>
                <span itemprop="about" itemscope itemtype="http://schema.org/Thing">
                  <a href="/categories/acm/" itemprop="url" rel="index"><span itemprop="name">acm</span></a>
                </span>
            </span>

          
            <span id="/2017/05/31/codeforces-round-416-div-2/" class="post-meta-item leancloud_visitors" data-flag-title="Codeforces Round #416 (Div. 2)" title="Views">
              <span class="post-meta-item-icon">
                <i class="fa fa-eye"></i>
              </span>
              <span class="post-meta-item-text">Views: </span>
              <span class="leancloud-visitors-count"></span>
            </span>
  
  <span class="post-meta-item">
    
      <span class="post-meta-item-icon">
        <i class="fa fa-comment-o"></i>
      </span>
      <span class="post-meta-item-text">Valine: </span>
    
    <a title="valine" href="/2017/05/31/codeforces-round-416-div-2/#valine-comments" itemprop="discussionUrl">
      <span class="post-comments-count valine-comment-count" data-xid="/2017/05/31/codeforces-round-416-div-2/" itemprop="commentCount"></span>
    </a>
  </span>
  
  

        </div>
      </header>

    
    
    
    <div class="post-body" itemprop="articleBody">

      
        <p><a target="_blank" rel="noopener" href="http://codeforces.com/contest/811/problem/A">A. Vladik and Courtesy</a> 二分查找一下次数就行 <span id="more"></span></p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;bits/stdc++.h&gt;</span></span></span><br><span class="line"><span class="keyword">using</span> <span class="keyword">namespace</span> std;</span><br><span class="line"><span class="keyword">long</span> <span class="keyword">long</span> a,b;</span><br><span class="line"><span class="function"><span class="keyword">long</span> <span class="keyword">long</span> <span class="title">ff1</span><span class="params">(<span class="keyword">long</span> <span class="keyword">long</span> x)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">long</span> <span class="keyword">long</span> l=<span class="number">0</span>;</span><br><span class="line">	<span class="keyword">long</span> <span class="keyword">long</span> r=<span class="number">27483600</span>;</span><br><span class="line">	<span class="keyword">while</span>(l&lt;r)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">long</span> <span class="keyword">long</span> mid=(l+r)/<span class="number">2</span>+<span class="number">1</span>;</span><br><span class="line">		<span class="keyword">if</span>(mid*mid&gt;x) r=mid<span class="number">-1</span>;</span><br><span class="line">		<span class="keyword">else</span> l=mid;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">return</span> l;</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">long</span> <span class="keyword">long</span> <span class="title">ff2</span><span class="params">(<span class="keyword">long</span> <span class="keyword">long</span> x)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">long</span> <span class="keyword">long</span> l=<span class="number">0</span>;</span><br><span class="line">	<span class="keyword">long</span> <span class="keyword">long</span> r=<span class="number">27483600</span>;</span><br><span class="line">	<span class="keyword">while</span>(l&lt;r)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">long</span> <span class="keyword">long</span> mid=(l+r)/<span class="number">2</span>+<span class="number">1</span>;</span><br><span class="line">		<span class="keyword">if</span>((mid+<span class="number">1</span>)*mid&gt;x) r=mid<span class="number">-1</span>;</span><br><span class="line">		<span class="keyword">else</span> l=mid;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">return</span> l;</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span> </span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	cin&gt;&gt;a&gt;&gt;b;</span><br><span class="line">	<span class="keyword">long</span> <span class="keyword">long</span> k1=<span class="built_in">ff1</span>(a);</span><br><span class="line">	<span class="keyword">long</span> <span class="keyword">long</span> k2=<span class="built_in">ff2</span>(b);</span><br><span class="line">	<span class="keyword">if</span>(k1&gt;k2)</span><br><span class="line">	&#123;</span><br><span class="line">		cout&lt;&lt;<span class="string">&quot;Valera&quot;</span>&lt;&lt;endl;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">else</span> cout&lt;&lt;<span class="string">&quot;Vladik&quot;</span>&lt;&lt;endl;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><a target="_blank" rel="noopener" href="http://codeforces.com/contest/811/problem/B">B. Vladik and Complicated Book</a> 暴力<span class="math inline">\(N^2\)</span>计数就行，很傻</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;bits/stdc++.h&gt;</span></span></span><br><span class="line"><span class="keyword">using</span> <span class="keyword">namespace</span> std;</span><br><span class="line"><span class="keyword">int</span> p[<span class="number">10010</span>];</span><br><span class="line"><span class="keyword">int</span> n,m;</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="built_in">scanf</span>(<span class="string">&quot;%d%d&quot;</span>,&amp;n,&amp;m);</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++) <span class="built_in">scanf</span>(<span class="string">&quot;%d&quot;</span>,&amp;p[i]);</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=m;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> l,r,x;</span><br><span class="line">		<span class="built_in">scanf</span>(<span class="string">&quot;%d%d%d&quot;</span>,&amp;l,&amp;r,&amp;x);</span><br><span class="line">		<span class="keyword">int</span> num=<span class="number">0</span>;</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> j=l;j&lt;=r;j++) <span class="keyword">if</span>(p[j]&lt;=p[x]) num++;</span><br><span class="line">		<span class="keyword">if</span>(num==(x-l+<span class="number">1</span>)) <span class="built_in">printf</span>(<span class="string">&quot;Yes\n&quot;</span>);</span><br><span class="line">		<span class="keyword">else</span> <span class="built_in">printf</span>(<span class="string">&quot;No\n&quot;</span>);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><a target="_blank" rel="noopener" href="http://codeforces.com/contest/811/problem/C">C. Vladik and Memorable Trip</a> 计算出要覆盖每个值的最小块的大小，然后标记一下。以为是最小块，所以两个块要么互相独立，要么包含，这样直接树dp，来选择块就行。</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;bits/stdc++.h&gt;</span></span></span><br><span class="line"><span class="keyword">using</span> <span class="keyword">namespace</span> std;</span><br><span class="line"><span class="keyword">int</span> n;</span><br><span class="line"><span class="keyword">int</span> a[<span class="number">5010</span>];</span><br><span class="line"><span class="keyword">int</span> ma[<span class="number">5010</span>];</span><br><span class="line"><span class="keyword">int</span> mi[<span class="number">5010</span>];</span><br><span class="line"><span class="keyword">int</span> pp[<span class="number">5010</span>];</span><br><span class="line">vector&lt;<span class="keyword">int</span>&gt; e[<span class="number">5010</span>];</span><br><span class="line"><span class="keyword">bool</span> b[<span class="number">5010</span>];</span><br><span class="line"><span class="keyword">int</span> t[<span class="number">5010</span>];</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">ff</span><span class="params">(<span class="keyword">int</span> x)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">int</span> ans=t[x];</span><br><span class="line">	<span class="keyword">int</span> ans1=<span class="number">0</span>;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">auto</span> &amp;i:e[x])</span><br><span class="line">	&#123;</span><br><span class="line">		ans1+=<span class="built_in">ff</span>(i);</span><br><span class="line">	&#125;</span><br><span class="line">	ans=<span class="built_in">max</span>(ans,ans1);</span><br><span class="line">	<span class="keyword">return</span> ans;</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="built_in">memset</span>(pp,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(pp));</span><br><span class="line">	cin&gt;&gt;n;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=<span class="number">5000</span>;i++) mi[i]=<span class="number">2147483600</span>,ma[i]=<span class="number">-1</span>;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++) cin&gt;&gt;a[i],mi[a[i]]=<span class="built_in">min</span>(i,mi[a[i]]),ma[a[i]]=<span class="built_in">max</span>(ma[a[i]],i);</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=<span class="number">5000</span>;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="built_in">memset</span>(b,<span class="number">0</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(b));</span><br><span class="line">		<span class="keyword">if</span>(ma[i]==<span class="number">-1</span>) <span class="keyword">continue</span>;</span><br><span class="line">		<span class="keyword">int</span> zz=mi[i];</span><br><span class="line">		<span class="keyword">int</span> yy=ma[i];</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> j=mi[i];j&lt;=ma[i];j++)</span><br><span class="line">		&#123;</span><br><span class="line">			zz=<span class="built_in">min</span>(zz,mi[a[j]]);</span><br><span class="line">			yy=<span class="built_in">max</span>(yy,ma[a[j]]);</span><br><span class="line">		&#125;</span><br><span class="line">		<span class="keyword">int</span> l=mi[i];</span><br><span class="line">		<span class="keyword">int</span> r=ma[i];</span><br><span class="line">		<span class="keyword">while</span>(l!=zz||r!=yy)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">if</span>(l!=zz)</span><br><span class="line">			&#123;</span><br><span class="line">				l--;</span><br><span class="line">				zz=<span class="built_in">min</span>(zz,mi[a[l]]);</span><br><span class="line">				yy=<span class="built_in">max</span>(yy,ma[a[l]]);</span><br><span class="line">			&#125;</span><br><span class="line">			<span class="keyword">if</span>(r!=yy)</span><br><span class="line">			&#123;</span><br><span class="line">				r++;</span><br><span class="line">				zz=<span class="built_in">min</span>(zz,mi[a[r]]);</span><br><span class="line">				yy=<span class="built_in">max</span>(yy,ma[a[r]]);</span><br><span class="line">			&#125;</span><br><span class="line">		&#125;</span><br><span class="line">		pp[yy]=<span class="number">-1</span>;</span><br><span class="line">		pp[zz]=yy-zz;</span><br><span class="line">		<span class="keyword">int</span> ans=<span class="number">0</span>;</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> j=l;j&lt;=r;j++)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">if</span>(b[a[j]]==<span class="number">0</span>)</span><br><span class="line">			&#123;</span><br><span class="line">				b[a[j]]=<span class="number">1</span>;</span><br><span class="line">				ans^=a[j];</span><br><span class="line">			&#125;</span><br><span class="line">		&#125;</span><br><span class="line">		t[l]=ans;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="comment">//cout&lt;&lt;i&lt;&lt;&quot; &quot;&lt;&lt;pp[i]&lt;&lt;endl;</span></span><br><span class="line">		<span class="keyword">if</span>(pp[i]==<span class="number">-1</span>) <span class="keyword">continue</span>;</span><br><span class="line">		<span class="keyword">int</span> l=i<span class="number">-1</span>;</span><br><span class="line">		<span class="keyword">while</span>(l!=<span class="number">0</span>&amp;&amp;pp[l]+l&lt;pp[i]+i)</span><br><span class="line">		&#123;</span><br><span class="line">			l--;</span><br><span class="line">		&#125;</span><br><span class="line">		e[l].<span class="built_in">push_back</span>(i);</span><br><span class="line">	&#125;</span><br><span class="line">	cout&lt;&lt;<span class="built_in">ff</span>(<span class="number">0</span>)&lt;&lt;endl;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><a target="_blank" rel="noopener" href="http://codeforces.com/contest/811/problem/D">D. Vladik and Favorite Game</a> 这是一道交互题。 交互题其实就是你输出一些东西，然后cf的程序会输入回一些东西，然后你通过这些，来搞一下你的下一步策略。 这个题其实很傻，就是先广搜出一条合理的路径，然后因为一定是先沿边走，所以瞎判断一下就行了。</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br><span class="line">97</span><br><span class="line">98</span><br><span class="line">99</span><br><span class="line">100</span><br><span class="line">101</span><br><span class="line">102</span><br><span class="line">103</span><br><span class="line">104</span><br><span class="line">105</span><br><span class="line">106</span><br><span class="line">107</span><br><span class="line">108</span><br><span class="line">109</span><br><span class="line">110</span><br><span class="line">111</span><br><span class="line">112</span><br><span class="line">113</span><br><span class="line">114</span><br><span class="line">115</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;bits/stdc++.h&gt;</span></span></span><br><span class="line"><span class="keyword">using</span> <span class="keyword">namespace</span> std;</span><br><span class="line"><span class="keyword">int</span> n,m;</span><br><span class="line"><span class="keyword">char</span> c[<span class="number">110</span>][<span class="number">110</span>];</span><br><span class="line"><span class="keyword">bool</span> v[<span class="number">110</span>][<span class="number">110</span>];</span><br><span class="line"><span class="keyword">int</span> d[<span class="number">110</span>][<span class="number">110</span>];</span><br><span class="line">pair&lt;<span class="keyword">int</span>,<span class="keyword">int</span>&gt; la[<span class="number">110</span>][<span class="number">110</span>];</span><br><span class="line"><span class="keyword">int</span> xx[<span class="number">4</span>]=&#123;<span class="number">1</span>,<span class="number">-1</span>,<span class="number">0</span>,<span class="number">0</span>&#125;;</span><br><span class="line"><span class="keyword">int</span> yy[<span class="number">4</span>]=&#123;<span class="number">0</span>,<span class="number">0</span>,<span class="number">1</span>,<span class="number">-1</span>&#125;;</span><br><span class="line">vector&lt;<span class="keyword">char</span>&gt; ans;</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	cin&gt;&gt;n&gt;&gt;m;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> j=<span class="number">1</span>;j&lt;=m;j++)</span><br><span class="line">		&#123;</span><br><span class="line">			cin&gt;&gt;c[i][j];</span><br><span class="line">			d[i][j]=<span class="number">2</span>*n*m;</span><br><span class="line">		&#125;</span><br><span class="line">	&#125;</span><br><span class="line">	queue&lt;pair&lt;<span class="keyword">int</span>,<span class="keyword">int</span>&gt; &gt; q;</span><br><span class="line">	q.<span class="built_in">push</span>(<span class="built_in">make_pair</span>(<span class="number">1</span>,<span class="number">1</span>));</span><br><span class="line">	v[<span class="number">1</span>][<span class="number">1</span>]=<span class="number">1</span>;</span><br><span class="line">	d[<span class="number">1</span>][<span class="number">1</span>]=<span class="number">0</span>;</span><br><span class="line">	<span class="keyword">while</span>(!q.<span class="built_in">empty</span>())</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> a=q.<span class="built_in">front</span>().first;</span><br><span class="line">		<span class="keyword">int</span> b=q.<span class="built_in">front</span>().second;</span><br><span class="line">		q.<span class="built_in">pop</span>();</span><br><span class="line">		v[a][b]=<span class="number">0</span>;</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">0</span>;i&lt;<span class="number">4</span>;i++)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">int</span> x=a+xx[i];</span><br><span class="line">			<span class="keyword">int</span> y=b+yy[i];</span><br><span class="line">			<span class="keyword">if</span>(x&lt;=<span class="number">0</span>||x&gt;n) <span class="keyword">continue</span>;</span><br><span class="line">			<span class="keyword">if</span>(y&lt;=<span class="number">0</span>||y&gt;m) <span class="keyword">continue</span>;</span><br><span class="line">			<span class="keyword">if</span>(c[x][y]==<span class="string">&#x27;*&#x27;</span>) <span class="keyword">continue</span>;</span><br><span class="line">			<span class="keyword">if</span>(d[a][b]+<span class="number">1</span>&lt;d[x][y])</span><br><span class="line">			&#123;</span><br><span class="line">				d[x][y]=d[a][b]+<span class="number">1</span>;</span><br><span class="line">				la[x][y]=<span class="built_in">make_pair</span>(a,b);</span><br><span class="line">				<span class="keyword">if</span>(v[x][y]==<span class="number">0</span>)</span><br><span class="line">				&#123;</span><br><span class="line">					v[x][y]=<span class="number">1</span>;</span><br><span class="line">					q.<span class="built_in">push</span>(<span class="built_in">make_pair</span>(x,y));</span><br><span class="line">				&#125;</span><br><span class="line">			&#125;</span><br><span class="line">		&#125;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">int</span> a,b;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> j=<span class="number">1</span>;j&lt;=m;j++)</span><br><span class="line">			<span class="keyword">if</span>(c[i][j]==<span class="string">&#x27;F&#x27;</span>)</span><br><span class="line">			&#123;</span><br><span class="line">				a=i;</span><br><span class="line">				b=j;</span><br><span class="line">			&#125;</span><br><span class="line">	<span class="keyword">while</span>(a!=<span class="number">1</span>||b!=<span class="number">1</span>)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> x,y;</span><br><span class="line">		x=la[a][b].first;</span><br><span class="line">		y=la[a][b].second;</span><br><span class="line">		<span class="keyword">if</span>(x&lt;a) ans.<span class="built_in">push_back</span>(<span class="string">&#x27;D&#x27;</span>);</span><br><span class="line">		<span class="keyword">if</span>(x&gt;a) ans.<span class="built_in">push_back</span>(<span class="string">&#x27;U&#x27;</span>);</span><br><span class="line">		<span class="keyword">if</span>(y&lt;b) ans.<span class="built_in">push_back</span>(<span class="string">&#x27;R&#x27;</span>);</span><br><span class="line">		<span class="keyword">if</span>(y&gt;b) ans.<span class="built_in">push_back</span>(<span class="string">&#x27;L&#x27;</span>);</span><br><span class="line">		a=x;</span><br><span class="line">		b=y;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">int</span> bj1=<span class="number">-1</span>;</span><br><span class="line">	<span class="keyword">int</span> bj2=<span class="number">-1</span>;</span><br><span class="line">	a=<span class="number">1</span>; b=<span class="number">1</span>;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=ans.<span class="built_in">size</span>()<span class="number">-1</span>;i&gt;=<span class="number">0</span>;i--)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span>(bj1==<span class="number">-1</span>&amp;&amp;c[a+<span class="number">1</span>][b]!=<span class="string">&#x27;*&#x27;</span>)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">int</span> pa=a;</span><br><span class="line">			cout&lt;&lt;<span class="string">&#x27;D&#x27;</span>&lt;&lt;endl;</span><br><span class="line">			<span class="built_in">fflush</span>(stdout);</span><br><span class="line">			cin&gt;&gt;a&gt;&gt;b;</span><br><span class="line">			<span class="keyword">if</span>(a!=pa)</span><br><span class="line">			&#123;</span><br><span class="line">				bj1=<span class="number">0</span>;</span><br><span class="line">				cout&lt;&lt;<span class="string">&#x27;U&#x27;</span>&lt;&lt;endl;</span><br><span class="line">				<span class="built_in">fflush</span>(stdout);</span><br><span class="line">				cin&gt;&gt;a&gt;&gt;b;</span><br><span class="line">			&#125;</span><br><span class="line">			<span class="keyword">else</span> bj1=<span class="number">1</span>;</span><br><span class="line">		&#125;</span><br><span class="line">		<span class="keyword">if</span>(bj2==<span class="number">-1</span>&amp;&amp;c[a][b+<span class="number">1</span>]!=<span class="string">&#x27;*&#x27;</span>)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">int</span> pb=b;;</span><br><span class="line">			cout&lt;&lt;<span class="string">&#x27;R&#x27;</span>&lt;&lt;endl;</span><br><span class="line">			<span class="built_in">fflush</span>(stdout);</span><br><span class="line">			cin&gt;&gt;a&gt;&gt;b;</span><br><span class="line">			<span class="keyword">if</span>(b!=pb)</span><br><span class="line">			&#123;</span><br><span class="line">				bj2=<span class="number">0</span>;</span><br><span class="line">				cout&lt;&lt;<span class="string">&#x27;L&#x27;</span>&lt;&lt;endl;</span><br><span class="line">				<span class="built_in">fflush</span>(stdout);</span><br><span class="line">				cin&gt;&gt;a&gt;&gt;b;</span><br><span class="line">			&#125;</span><br><span class="line">			<span class="keyword">else</span> bj2=<span class="number">1</span>;</span><br><span class="line">		&#125;</span><br><span class="line">		<span class="keyword">if</span>(ans[i]==<span class="string">&#x27;U&#x27;</span>&amp;&amp;bj1==<span class="number">1</span>) ans[i]=<span class="string">&#x27;D&#x27;</span>;</span><br><span class="line">		<span class="keyword">else</span> <span class="keyword">if</span>(ans[i]==<span class="string">&#x27;D&#x27;</span>&amp;&amp;bj1==<span class="number">1</span>) ans[i]=<span class="string">&#x27;U&#x27;</span>;</span><br><span class="line">		<span class="keyword">else</span> <span class="keyword">if</span>(ans[i]==<span class="string">&#x27;L&#x27;</span>&amp;&amp;bj2==<span class="number">1</span>) ans[i]=<span class="string">&#x27;R&#x27;</span>;</span><br><span class="line">		<span class="keyword">else</span> <span class="keyword">if</span>(ans[i]==<span class="string">&#x27;R&#x27;</span>&amp;&amp;bj2==<span class="number">1</span>) ans[i]=<span class="string">&#x27;L&#x27;</span>;</span><br><span class="line">		cout&lt;&lt;ans[i]&lt;&lt;endl;</span><br><span class="line">		<span class="built_in">fflush</span>(stdout);</span><br><span class="line">		cin&gt;&gt;a&gt;&gt;b;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p><a target="_blank" rel="noopener" href="http://codeforces.com/contest/811/problem/E">E. Vladik and Entertaining Flags</a> 不错的一道题。 用线段树维护一下左边界和右边界总共2*n个点的并查集，然后做一下并查集的合并。 说起来蛮简单的，但是合并的细节有点多，写起来也有点烦。（可能我的写法比较糟糕）</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br><span class="line">97</span><br><span class="line">98</span><br><span class="line">99</span><br><span class="line">100</span><br><span class="line">101</span><br><span class="line">102</span><br><span class="line">103</span><br><span class="line">104</span><br><span class="line">105</span><br><span class="line">106</span><br><span class="line">107</span><br><span class="line">108</span><br><span class="line">109</span><br><span class="line">110</span><br><span class="line">111</span><br><span class="line">112</span><br><span class="line">113</span><br><span class="line">114</span><br><span class="line">115</span><br><span class="line">116</span><br><span class="line">117</span><br><span class="line">118</span><br><span class="line">119</span><br><span class="line">120</span><br><span class="line">121</span><br><span class="line">122</span><br><span class="line">123</span><br><span class="line">124</span><br><span class="line">125</span><br><span class="line">126</span><br><span class="line">127</span><br><span class="line">128</span><br><span class="line">129</span><br><span class="line">130</span><br><span class="line">131</span><br><span class="line">132</span><br><span class="line">133</span><br><span class="line">134</span><br><span class="line">135</span><br><span class="line">136</span><br><span class="line">137</span><br><span class="line">138</span><br><span class="line">139</span><br><span class="line">140</span><br><span class="line">141</span><br><span class="line">142</span><br><span class="line">143</span><br><span class="line">144</span><br><span class="line">145</span><br><span class="line">146</span><br><span class="line">147</span><br><span class="line">148</span><br><span class="line">149</span><br><span class="line">150</span><br><span class="line">151</span><br><span class="line">152</span><br><span class="line">153</span><br><span class="line">154</span><br><span class="line">155</span><br><span class="line">156</span><br><span class="line">157</span><br><span class="line">158</span><br><span class="line">159</span><br><span class="line">160</span><br><span class="line">161</span><br><span class="line">162</span><br><span class="line">163</span><br><span class="line">164</span><br><span class="line">165</span><br><span class="line">166</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="meta-keyword">include</span><span class="meta-string">&lt;bits/stdc++.h&gt;</span></span></span><br><span class="line"><span class="keyword">using</span> <span class="keyword">namespace</span> std;</span><br><span class="line"><span class="keyword">int</span> n,m,q;</span><br><span class="line"><span class="keyword">int</span> c[<span class="number">15</span>][<span class="number">100010</span>];</span><br><span class="line"><span class="class"><span class="keyword">struct</span> <span class="title">seg</span></span></span><br><span class="line"><span class="class">&#123;</span></span><br><span class="line">	<span class="keyword">int</span> u[<span class="number">22</span>];</span><br><span class="line">	<span class="keyword">int</span> l,r;</span><br><span class="line">	<span class="keyword">int</span> num;</span><br><span class="line">&#125;;</span><br><span class="line">seg e[<span class="number">400040</span>];</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">init</span><span class="params">(<span class="keyword">int</span> (&amp;f)[<span class="number">22</span>])</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=<span class="number">2</span>*n;i++) f[i]=i;</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">ff</span><span class="params">(<span class="keyword">int</span> (&amp;f)[<span class="number">22</span>],<span class="keyword">int</span> x)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">if</span>(x==f[x]) <span class="keyword">return</span> x;</span><br><span class="line">	f[x]=<span class="built_in">ff</span>(f,f[x]);</span><br><span class="line">	<span class="keyword">return</span> f[x];</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">merge</span><span class="params">(<span class="keyword">int</span> (&amp;f)[<span class="number">22</span>],<span class="keyword">int</span> x,<span class="keyword">int</span> y)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	f[<span class="built_in">ff</span>(f,x)]=<span class="built_in">ff</span>(f,y);</span><br><span class="line">&#125;</span><br><span class="line"><span class="keyword">int</span> t[<span class="number">42</span>];</span><br><span class="line"><span class="keyword">int</span> w[<span class="number">44</span>];</span><br><span class="line"><span class="keyword">int</span> p[<span class="number">22</span>];</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">ff1</span><span class="params">(<span class="keyword">int</span> x)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">if</span>(t[x]==x) <span class="keyword">return</span> x;</span><br><span class="line">	t[x]=<span class="built_in">ff1</span>(t[x]);</span><br><span class="line">	<span class="keyword">return</span> t[x];</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">mergedsu</span><span class="params">(seg &amp;a,seg &amp;b,seg &amp;e)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="built_in">init</span>(a.u);</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=<span class="number">4</span>*n;i++) t[i]=i;</span><br><span class="line">	a.num=b.num+e.num;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span>(c[i][b.r]==c[i][e.l]&amp;&amp;(<span class="built_in">ff1</span>(<span class="built_in">ff</span>(b.u,i+n))!=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(e.u,i)+<span class="number">2</span>*n)))</span><br><span class="line">		&#123;</span><br><span class="line">			t[<span class="built_in">ff1</span>(<span class="built_in">ff</span>(b.u,i+n))]=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(e.u,i)+<span class="number">2</span>*n);</span><br><span class="line">			a.num--;</span><br><span class="line">		&#125;</span><br><span class="line">	&#125;</span><br><span class="line">	a.l=b.l; a.r=e.r;</span><br><span class="line">	<span class="built_in">memset</span>(p,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(p));</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff</span>(b.u,i);</span><br><span class="line">		<span class="keyword">if</span>(p[tt]==<span class="number">-1</span>) p[tt]=i;</span><br><span class="line">		<span class="keyword">else</span> <span class="built_in">merge</span>(a.u,p[tt],i);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">memset</span>(p,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(p));</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff</span>(e.u,i+n);</span><br><span class="line">		<span class="keyword">if</span>(p[tt]==<span class="number">-1</span>) p[tt]=i+n;</span><br><span class="line">		<span class="keyword">else</span> <span class="built_in">merge</span>(a.u,p[tt],i+n);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">memset</span>(w,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(w));</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(e.u,i+n)+<span class="number">2</span>*n);</span><br><span class="line">		w[tt]=i+n;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(b.u,i));</span><br><span class="line">		<span class="keyword">if</span>(w[tt]!=<span class="number">-1</span>) <span class="built_in">merge</span>(a.u,i,w[tt]);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">memset</span>(w,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(w));</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(b.u,i));</span><br><span class="line">		w[tt]=i;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(e.u,i+n)+<span class="number">2</span>*n);</span><br><span class="line">		<span class="keyword">if</span>(w[tt]!=<span class="number">-1</span>) <span class="built_in">merge</span>(a.u,i+n,w[tt]);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">memset</span>(w,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(w));</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(b.u,i));</span><br><span class="line">		w[tt]=i;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(b.u,i));</span><br><span class="line">		<span class="keyword">if</span>(w[tt]!=<span class="number">-1</span>) <span class="built_in">merge</span>(a.u,i,w[tt]);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">memset</span>(w,<span class="number">-1</span>,<span class="built_in"><span class="keyword">sizeof</span></span>(w));</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(e.u,i+n)+<span class="number">2</span>*n);</span><br><span class="line">		w[tt]=i+n;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">int</span> tt=<span class="built_in">ff1</span>(<span class="built_in">ff</span>(e.u,i+n)+<span class="number">2</span>*n);</span><br><span class="line">		<span class="keyword">if</span>(w[tt]!=<span class="number">-1</span>) <span class="built_in">merge</span>(a.u,i+n,w[tt]);</span><br><span class="line">	&#125;</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">build</span><span class="params">(<span class="keyword">int</span> x,<span class="keyword">int</span> l,<span class="keyword">int</span> r)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">if</span>(l==r)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="built_in">init</span>(e[x].u);</span><br><span class="line">		e[x].l=l; e[x].r=r;</span><br><span class="line">		e[x].num=<span class="number">0</span>;</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">if</span>(c[i][l]==c[i<span class="number">-1</span>][l]) <span class="built_in">merge</span>(e[x].u,i,i<span class="number">-1</span>);</span><br><span class="line">			<span class="keyword">else</span> e[x].num++;</span><br><span class="line">			<span class="built_in">merge</span>(e[x].u,i,i+n);</span><br><span class="line">		&#125;</span><br><span class="line">		<span class="keyword">return</span>;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">int</span> mid=(l+r)/<span class="number">2</span>;</span><br><span class="line">	<span class="built_in">build</span>(x*<span class="number">2</span>,l,mid);</span><br><span class="line">	<span class="built_in">build</span>(x*<span class="number">2</span>+<span class="number">1</span>,mid+<span class="number">1</span>,r);</span><br><span class="line">	<span class="built_in">mergedsu</span>(e[x],e[x*<span class="number">2</span>],e[x*<span class="number">2</span>+<span class="number">1</span>]);</span><br><span class="line">	<span class="keyword">return</span>;</span><br><span class="line">&#125;</span><br><span class="line">seg ans;</span><br><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">query</span><span class="params">(<span class="keyword">int</span> x,<span class="keyword">int</span> l,<span class="keyword">int</span> r,<span class="keyword">int</span> z,<span class="keyword">int</span> y)</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">if</span>(z&lt;=l&amp;&amp;y&gt;=r)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span>(z==l) ans=e[x];</span><br><span class="line">		<span class="keyword">else</span></span><br><span class="line">		&#123;</span><br><span class="line">			seg u;</span><br><span class="line">			<span class="built_in">mergedsu</span>(u,ans,e[x]);</span><br><span class="line">			ans=u;</span><br><span class="line">		&#125;</span><br><span class="line">		<span class="keyword">return</span>;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">int</span> mid=(l+r)/<span class="number">2</span>;</span><br><span class="line">	<span class="keyword">if</span>(z&lt;=mid) <span class="built_in">query</span>(x*<span class="number">2</span>,l,mid,z,y);</span><br><span class="line">	<span class="keyword">if</span>(y&gt;mid) <span class="built_in">query</span>(x*<span class="number">2</span>+<span class="number">1</span>,mid+<span class="number">1</span>,r,z,y);</span><br><span class="line">&#125;</span><br><span class="line"><span class="function"><span class="keyword">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="built_in">scanf</span>(<span class="string">&quot;%d%d%d&quot;</span>,&amp;n,&amp;m,&amp;q);</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=n;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">for</span>(<span class="keyword">int</span> j=<span class="number">1</span>;j&lt;=m;j++)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="built_in">scanf</span>(<span class="string">&quot;%d&quot;</span>,&amp;c[i][j]);</span><br><span class="line">		&#125;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">build</span>(<span class="number">1</span>,<span class="number">1</span>,m);</span><br><span class="line">	<span class="keyword">int</span> l,r;</span><br><span class="line">	<span class="keyword">for</span>(<span class="keyword">int</span> i=<span class="number">1</span>;i&lt;=q;i++)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="built_in">scanf</span>(<span class="string">&quot;%d%d&quot;</span>,&amp;l,&amp;r);</span><br><span class="line">		<span class="built_in">query</span>(<span class="number">1</span>,<span class="number">1</span>,m,l,r);</span><br><span class="line">		<span class="built_in">printf</span>(<span class="string">&quot;%d\n&quot;</span>,ans.num);</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

    </div>

    
    
    

      <footer class="post-footer">
          <div class="post-tags">
              <a href="/tags/codeforces/" rel="tag"># codeforces</a>
              <a href="/tags/%E6%A0%91DP/" rel="tag"># 树DP</a>
              <a href="/tags/%E5%B9%B6%E6%9F%A5%E9%9B%86/" rel="tag"># 并查集</a>
              <a href="/tags/%E4%BA%8C%E5%88%86%E6%9F%A5%E6%89%BE/" rel="tag"># 二分查找</a>
              <a href="/tags/%E4%BA%A4%E4%BA%92%E9%A2%98/" rel="tag"># 交互题</a>
          </div>

        


        
    <div class="post-nav">
      <div class="post-nav-item">
    <a href="/2017/05/16/playrix-codescapes-cup-codeforces-round-413-rated-div-1-div-2/" rel="prev" title="Playrix Codescapes Cup (Codeforces Round #413, rated, Div. 1 + Div. 2)">
      <i class="fa fa-chevron-left"></i> Playrix Codescapes Cup (Codeforces Round #413, rated, Div. 1 + Div. 2)
    </a></div>
      <div class="post-nav-item">
    <a href="/2017/06/04/%E8%AE%A1%E8%92%9C%E4%B9%8B%E9%81%932017/" rel="next" title="计蒜之道2017">
      计蒜之道2017 <i class="fa fa-chevron-right"></i>
    </a></div>
    </div>
      </footer>
    
  </article>
  
  
  



          </div>
          
    <div class="comments" id="valine-comments"></div>

<script>
  window.addEventListener('tabs:register', () => {
    let { activeClass } = CONFIG.comments;
    if (CONFIG.comments.storage) {
      activeClass = localStorage.getItem('comments_active') || activeClass;
    }
    if (activeClass) {
      let activeTab = document.querySelector(`a[href="#comment-${activeClass}"]`);
      if (activeTab) {
        activeTab.click();
      }
    }
  });
  if (CONFIG.comments.storage) {
    window.addEventListener('tabs:click', event => {
      if (!event.target.matches('.tabs-comment .tab-content .tab-pane')) return;
      let commentClass = event.target.classList[1];
      localStorage.setItem('comments_active', commentClass);
    });
  }
</script>

        </div>
          
  
  <div class="toggle sidebar-toggle">
    <span class="toggle-line toggle-line-first"></span>
    <span class="toggle-line toggle-line-middle"></span>
    <span class="toggle-line toggle-line-last"></span>
  </div>

  <aside class="sidebar">
    <div class="sidebar-inner">

      <ul class="sidebar-nav motion-element">
        <li class="sidebar-nav-toc">
          Table of Contents
        </li>
        <li class="sidebar-nav-overview">
          Overview
        </li>
      </ul>

      <!--noindex-->
      <div class="post-toc-wrap sidebar-panel">
      </div>
      <!--/noindex-->

      <div class="site-overview-wrap sidebar-panel">
        <div class="site-author motion-element" itemprop="author" itemscope itemtype="http://schema.org/Person">
  <p class="site-author-name" itemprop="name">Reku</p>
  <div class="site-description" itemprop="description"></div>
</div>
<div class="site-state-wrap motion-element">
  <nav class="site-state">
      <div class="site-state-item site-state-posts">
          <a href="/archives/">
        
          <span class="site-state-item-count">78</span>
          <span class="site-state-item-name">posts</span>
        </a>
      </div>
      <div class="site-state-item site-state-categories">
            <a href="/categories/">
        <span class="site-state-item-count">8</span>
        <span class="site-state-item-name">categories</span></a>
      </div>
      <div class="site-state-item site-state-tags">
            <a href="/tags/">
          
        <span class="site-state-item-count">96</span>
        <span class="site-state-item-name">tags</span></a>
      </div>
  </nav>
</div>
  <div class="links-of-author motion-element">
      <span class="links-of-author-item">
        <a href="https://github.com/wyc-ruiker" title="GitHub → https:&#x2F;&#x2F;github.com&#x2F;wyc-ruiker" rel="noopener" target="_blank"><i class="fa fa-fw fa-github"></i>GitHub</a>
      </span>
      <span class="links-of-author-item">
        <a href="https://www.zhihu.com/people/reku1997" title="ZhiHu → https:&#x2F;&#x2F;www.zhihu.com&#x2F;people&#x2F;reku1997" rel="noopener" target="_blank"><i class="fa fa-fw fa-quora"></i>ZhiHu</a>
      </span>
      <span class="links-of-author-item">
        <a href="http://codeforces.com/profile/reku" title="CodeForces → http:&#x2F;&#x2F;codeforces.com&#x2F;profile&#x2F;reku" rel="noopener" target="_blank"><i class="fa fa-fw fa-code"></i>CodeForces</a>
      </span>
      <span class="links-of-author-item">
        <a href="https://www.linkedin.cn/injobs/in/reku" title="Linkedin → https:&#x2F;&#x2F;www.linkedin.cn&#x2F;injobs&#x2F;in&#x2F;reku" rel="noopener" target="_blank"><i class="fa fa-fw fa-linkedin"></i>Linkedin</a>
      </span>
      <span class="links-of-author-item">
        <a href="https://gitee.com/reku1997" title="Gitee → https:&#x2F;&#x2F;gitee.com&#x2F;reku1997" rel="noopener" target="_blank"><i class="fa fa-fw fa-github"></i>Gitee</a>
      </span>
      <span class="links-of-author-item">
        <a href="/./atom.xml" title="RSS → .&#x2F;atom.xml"><i class="fa fa-fw fa-rss"></i>RSS</a>
      </span>
  </div>



      </div>

    </div>
  </aside>
  <div id="sidebar-dimmer"></div>


      </div>
    </main>

    <footer class="footer">
      <div class="footer-inner">
        

        

<div class="copyright">
  
  &copy; 2016 – 
  <span itemprop="copyrightYear">2022</span>
  <span class="with-love">
    <i class="fa fa-user"></i>
  </span>
  <span class="author" itemprop="copyrightHolder">Reku</span>
</div>
  <div class="powered-by">Powered by <a href="https://hexo.io/" class="theme-link" rel="noopener" target="_blank">Hexo</a> & <a href="https://theme-next.org/" class="theme-link" rel="noopener" target="_blank">NexT.Gemini</a>
  </div>

        
<div class="busuanzi-count">
  <script async src="https://busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js"></script>
    <span class="post-meta-item" id="busuanzi_container_site_uv" style="display: none;">
      <span class="post-meta-item-icon">
        <i class="fa fa-user"></i>
      </span>
      <span class="site-uv" title="Total Visitors">
        <span id="busuanzi_value_site_uv"></span>
      </span>
    </span>
    <span class="post-meta-divider">|</span>
    <span class="post-meta-item" id="busuanzi_container_site_pv" style="display: none;">
      <span class="post-meta-item-icon">
        <i class="fa fa-eye"></i>
      </span>
      <span class="site-pv" title="Total Views">
        <span id="busuanzi_value_site_pv"></span>
      </span>
    </span>
</div>








      </div>
    </footer>
  </div>

  
  <script src="/lib/anime.min.js"></script>
  <script src="/lib/velocity/velocity.min.js"></script>
  <script src="/lib/velocity/velocity.ui.min.js"></script>

<script src="/js/utils.js"></script>

<script src="/js/motion.js"></script>


<script src="/js/schemes/pisces.js"></script>


<script src="/js/next-boot.js"></script>




  




  
<script src="//cdn.jsdelivr.net/npm/algoliasearch@4/dist/algoliasearch-lite.umd.js"></script>
<script src="//cdn.jsdelivr.net/npm/instantsearch.js@4/dist/instantsearch.production.min.js"></script>
<script src="/js/algolia-search.js"></script>














  

  
      

<script>
  if (typeof MathJax === 'undefined') {
    window.MathJax = {
      loader: {
        source: {
          '[tex]/amsCd': '[tex]/amscd',
          '[tex]/AMScd': '[tex]/amscd'
        }
      },
      tex: {
        inlineMath: {'[+]': [['$', '$']]},
        tags: 'ams'
      },
      options: {
        renderActions: {
          findScript: [10, doc => {
            document.querySelectorAll('script[type^="math/tex"]').forEach(node => {
              const display = !!node.type.match(/; *mode=display/);
              const math = new doc.options.MathItem(node.textContent, doc.inputJax[0], display);
              const text = document.createTextNode('');
              node.parentNode.replaceChild(text, node);
              math.start = {node: text, delim: '', n: 0};
              math.end = {node: text, delim: '', n: 0};
              doc.math.push(math);
            });
          }, '', false],
          insertedScript: [200, () => {
            document.querySelectorAll('mjx-container').forEach(node => {
              let target = node.parentNode;
              if (target.nodeName.toLowerCase() === 'li') {
                target.parentNode.classList.add('has-jax');
              }
            });
          }, '', false]
        }
      }
    };
    (function () {
      var script = document.createElement('script');
      script.src = '//cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js';
      script.defer = true;
      document.head.appendChild(script);
    })();
  } else {
    MathJax.startup.document.state(0);
    MathJax.texReset();
    MathJax.typeset();
  }
</script>

    

  


<script>
NexT.utils.loadComments(document.querySelector('#valine-comments'), () => {
  NexT.utils.getScript('//unpkg.com/valine/dist/Valine.min.js', () => {
    var GUEST = ['nick', 'mail', 'link'];
    var guest = 'nick,mail,link';
    guest = guest.split(',').filter(item => {
      return GUEST.includes(item);
    });
    new Valine({
      el         : '#valine-comments',
      verify     : false,
      notify     : false,
      appId      : 'MWLzM550UOu69h3dgvbbLSsF-gzGzoHsz',
      appKey     : 'gkKnwm9FK0cu3ysJbcggsCDz',
      placeholder: "Just go go",
      avatar     : 'mm',
      meta       : guest,
      pageSize   : '10' || 10,
      visitor    : true,
      lang       : '' || 'zh-cn',
      path       : location.pathname,
      recordIP   : false,
      serverURLs : ''
    });
  }, window.Valine);
});
</script>

</body>
</html>
